Paste compositions (II)

Abstract

Paste compositions with a water content of no more than 2% by weight, containing and / or consisting of (a) at least one colour pigment and / or one filler, (b) at least one alkoxylated alcohol and, if applicable (c) at least one dispersant.

Description

AREA OF INVENTION

[0001] The invention is in the field of paints and coatings and essentially relates to water- and solvent-free pigment paste formulations containing color pigments together with novel viscosity regulators. TECHNOLOGICAL BACKGROUND

[0002] Both professional painters and decorators, as well as DIY enthusiasts, enjoy the time-saving and highly precise method of achieving a desired color by mixing pigment pastes with base paints and varnishes. Hardware stores, in particular, utilize dispensing machines that contain a large number of color pastes. These machines allow users to quickly and consistently produce the desired color based on a formula database by selecting the appropriate pigment paste type and quantity, along with the corresponding base paints and varnishes.

[0003] With these so-called color mixing systems, two parameters are critical: firstly, the accuracy of color production depends on the number of pigment pastes available with different pigment types (color indices) and concentrations. The more different color pastes are available, the larger the achievable color gamut, but the more space is required on the system. Secondly, the pigment pastes are not all needed with the same frequency or in the same quantities, which means that some colors can remain in their containers for months, promoting bacterial growth and drying out of conventional pigment pastes.

[0004] To keep the amount of paste on the mixing machines low, highly concentrated pigment pastes are used, which contain as little water or solvent as possible and therefore require less storage space. However, as the amount of solvent decreases, the viscosity increases, which makes dosing more difficult or sometimes impossible.

[0005] While the problem of microbial contamination can be solved by eliminating water as a solvent, this necessitates either switching to solvent-based systems – which again requires more space and is undesirable from an ecotoxicological perspective – or adding biocides to the pigment pastes. However, biocide-containing systems are increasingly viewed critically by consumers and, in particular, cannot be awarded the "Blue Angel" ecolabel.

[0006] In aqueous systems, the drying out of pigment pastes is countered by the use of humectants, while in solvent-based pastes, solvents with a lower evaporation rate are used. RELEVANT STATE OF THE TECHNOLOGY

[0007] Monoepoxide monoamine adducts are known from WO 2018 184961 A1 (BYK) as dispersants and wetting agents for colour pigments.

[0008] Polyurethane-based copolymers are proposed in WO 2015 090811 A1 (BASF) for the same purpose.

[0009] The subject of WO 2018 157965 A1 (THOR) is the use of 5-chloro-2-methylisothiazolin as a biocide for the preservation of technical products including pigment pastes. TASK OF INVENTION

[0010] The object of the present invention was therefore to provide pigment pastes, preferably both water- and solvent-free (so-called "100 percent") systems, which, despite the absence of solvents, exhibit a sufficiently low viscosity so that they are easily flowable and pumpable. Furthermore, the preparations should contain only essential components that meet the requirements of the RAL UZ 102 "Blue Angel" ecolabel for tinting products. These include, for example, the absence of biocides, plasticizers, substances of very high concern (SVHCs), and water-polluting substances. DESCRIPTION OF THE INVENTION

[0011] The invention relates to paste compositions containing and / or consisting of (a) at least one colour pigment and / or one filler, (b) at least one alkoxylated alcohol, and where appropriate (c) at least one dispersant.

[0012] Surprisingly, it was found that alkoxylated alcohols allow the production of free-flowing and pumpable pigment and filler pastes with a solids content of up to 80% by weight. Free-flowing and pumpable in this context means that the pastes have a viscosity (plate / plate, 20°C) of less than 1,000 mPas at a shear rate of 500 s and less than 20,000 mPas at 1 s. The pastes are considered anhydrous, containing at most up to 2% by weight of water, which is introduced via the pigments or, if applicable, the residual moisture of the alkoxylates and / or dispersants. They are also free of solvents and plasticizers. Since they meet the requirements of RAL UZ 102 for constitutional components of tinting products, the pigment preparations are highly suitable for tinting base paints and varnishes bearing the "Blue Angel" ecolabel. Paste compositions

[0013] The pastes may contain pigments, especially color pigments, or fillers, which can be of inorganic or organic origin; their selection is largely uncritical and depends solely on the intended use. They can be intended for later use in paints as well as varnishes. Examples of organic pigments are arylide yellow (CI 11741), phthalocyanine green (CI 74260), phthalocyanine blue (CI 74160), diketopyrrolopyrrole (CI 56110), and carbazole violet (CI 51319). The preferred inorganic pigments are titanium dioxide (CI 77891), iron oxide red (CI 77491), iron oxide yellow (CI 77492), and bismuth vanadate (CI 771740). In addition, carbon black (CI 77266) or other colored mixed metal oxides—provided they are toxicologically safe—may also be used. Examples of fillers used to adjust application-related properties such as density and viscosity include calcium carbonate (CI77220), barium sulfate (CI77120), and talc (CI77120).77718) or also kaolin (C.1.77004) is used. Alkoxylated alcohols

[0014] Polyalkylene glycol ethers are well-known products that can be prepared using standard methods of preparative organic chemistry. For example, a starting alcohol is added and reacted with ethylene oxide or propylene oxide at pressures in the range of, for example, 2 to 10 bar and temperatures of, for example, 50 to 150 °C. Mixtures of ethylene and propylene oxide can also be used; this results in a random distribution of the ethylene and propylene oxide units along the polyether chain. If ethylene and propylene oxide are added sequentially or alternately, a block distribution is obtained in the polyether chain.

[0015] Suitable alkoxylated alcohols typically follow formula (II) R 2 (AO) m OH (II) in the R 2 for a linear or branched hydrocarbon radical with 1 to 22 carbon atoms, which may have up to 3 double bonds, AO for an ethylene glycol or propylene glycol unit or a mixture of ethylene glycol and propylene glycol units in block or random sequence, and m stands for whole numbers from 1 to 30.

[0016] The preferred starting alcohols (according to a formula R) 2 OH) include, in particular, native or synthetic fatty alcohols with 6 to 22 carbon atoms, but also low-molecular-weight alcohols with 1 to 5 carbon atoms. The alcohols can also be mono- or polyunsaturated and branched. EO or PO adducts of alcohols can also be used as starting materials; butyldiglycol and butyltriglycol are particularly suitable.

[0017] Particularly preferred are alkoxylates of butanol and its adducts butyldiglycol and butyltriglycol with a mean molar mass of 900 to 1200 g / mol and an EO / PO ratio of 1:1 to 2:1 as a random distribution. The statistical molar mass distribution should be as narrow as possible and contain few low molecular weight components.

[0018] Polyglycol allialkyl ethers are also suitable. These products differ from polyalkylene glycols by a reactive double bond in the molecule. This double bond can later crosslink in an oxidatively drying binder when the tinting pastes are applied, significantly increasing the film hardness of the system. Amine compounds as dispersants

[0019] Although the addition of alkoxylated carboxylic acids alone reduces the viscosity of even highly concentrated pigment pastes so significantly that they become flowable and pumpable even in the absence of water or organic solvents, this effect can be further enhanced by using specific amine compounds as dispersants. The ratio of additive to co-additive can range from 50:50 to 95:5, and preferably from 80:20 to 90:10.

[0020] The amine compounds can be aliphatic, aromatic, or araliphatic. The nitrogen can also be part of a ring. The compounds can be primary, secondary, or tertiary amines and have 1 to 20 carbon atoms per nitrogen substituent.

[0021] Suitable amine compounds follow in a first embodiment of formula (IV) in the R 3 for -(CHY) x (NH) y (CHY)2A, x and y each for integers from 1 to 10, preferably 1 to 5, y for 0 or 1, Y represents hydrogen or an alkyl group with 1 to 4 carbon atoms, A for hydrogen, a hydroxyl group, an amino group or an (OCH2CHY)p group P for integers from 1 to 10 and R 4 and R 5 independently of each other for hydrogen or R 1 stand.

[0022] Suitable examples are in particular the addition products of 1 to 25, preferably 2 to 5 mol of ethylene oxide and / or propylene oxide (in random or block distribution) to methylamine, dimethylamine, ethylamine, diethylamine, propylamine, dipropylamine, butylamine, dibutylamine, methylethylamine, diethyleneamine, dipropylenamine, ethanolamine, diethanolamine, triethanolamine and mixtures thereof. Pigment pastes

[0023] In a first preferred embodiment, paste compositions are preferred which (a) about 5 to about 80 wt.%, preferably about 10 to about 75 wt.% and in particular about 25 to about 60 wt.% color pigments and / or fillers and (b) about 20 to about 95 wt.%, preferably about 25 to about 90 wt.% and in particular about 40 to about 75 wt.% alkoxylated alcohols. with the stipulation that the quantities may be supplemented with further additives to reach 100% by weight.

[0024] A second embodiment prefers paste compositions which (a) about 5 to about 80 wt.%, preferably about 10 to about 75 wt.% and in particular about 25 to about 60 wt.% colour pigments and / or fillers; (b) about 20 to about 90 wt.%, preferably about 25 to 80 wt.% and in particular about 40 to 75 wt.% alkoxylated alcohols as well as (c) containing about 1 to about 7 wt.%, preferably about 2 to about 5 wt.% dispersants, with the provision that the amounts may be supplemented with further additives to 100 wt.%.

[0025] To avoid any ambiguity, it should be noted that preparations derived from the specified quantity ranges, but which do not supplement each other to 100% by weight or exceed 100% by weight, are not covered by the invention. Within the specified ranges, a person skilled in the art can find suitable compositions that supplement each other to 10% by weight and fulfill the technical teaching without having to make an inventive step.

[0026] Preferably, the paste compositions according to the invention are anhydrous; however, they may have a total water content of a maximum of 2 wt.% and preferably a maximum of 1 wt.% if the color pigments and fillers used, as well as the alkoxylates and dispersants, have a residual water content.

[0027] The paste compositions according to the invention meet the requirements of the RAL ZU 102 “Blue Angel” ecolabel for tinting products. These include, for example, the absence of biocides, plasticizers, SVHCs, and water-polluting substances. They also meet the requirements for classification in water hazard class (WGK) 1.

[0028] The paste compositions are further characterized by having a viscosity (plate / plate, 20 °C) of less than 1,000 mPas at a shear rate of 500 1 / s and less than 20,000 mPas at 1 1 / s. COMMERCIAL APPLICABILITY

[0029] Furthermore, a method for producing water- and solvent-free paste compositions is disclosed, comprising or consisting of the following steps: (a) Providing at least one inorganic or organic pigment or filler; (b) Providing at least one alkoxylated alcohol; (c) where appropriate, providing at least one disperser; and (d) Homogenizing and dispersing components (a), (b) and, if applicable, (c).

[0030] The use of alkoxylated alcohols, optionally together with dispersants, as additives for the production of water- and solvent-free pigment pastes is also disclosed.

[0031] Preferably, the alkoxylated alcohols represent adducts of ethylene oxide and / or propylene oxide to butanol, butyldiglycol and / or butyltriglycol with a mean molar mass of 900 - 1200 g / mol and an EO / PO ratio of 1:1 to 2:1 as a random distribution.

[0032] Titanium dioxide was incorporated into various liquid alkoxylate / dispersant mixtures under high shear to obtain pigment pastes with a TiO₂ concentration of 70 wt%. The viscosity of the pastes was determined at shear rates of 1, 10, 100, and 500 reciprocal seconds. (Instrument: HAAKE MARS III; plate / plate with a 35 mm diameter (P35 Ti L), d = 0.300 mm, T = 20°C ±0.1, CR from 0.1 to 1000 1 / s, followed by CR from 1000 to 0.1 1 / s with measurements recorded on the back-curve.) The results are summarized in Table 1. Table 1 Viscosity of 70 wt% TiO2 pastes (* = viscosity > 100,000 mPas) composition 1 2 3 V1 V2 C 12 -Fattyalcohol+PO+EO - - - 30,0 28,0 Butanol+PO / EO (1:1, random, approx. 1 kDa) 30.0 28,0 28,0 - - Diethylamine + PO + EO - 2,0 - 2,0 - - SMA / Sulfonamine / API - - 2,0 - -2,0 Kronos 2310 TiO2 Pigment 70.0 70,0 70,0 70,0 70,0 sum 100,0 100,0 100,0 100,0 100,0 Viscosity (mPas) 1 / s - 100800 1507 nm nm 10 / s 29780 11650 1305 nm nm 100 / s 4740 2637 1399 nm nm 500 / s 3679 2494 1721 nm nm

[0033] The examples and comparisons show that butanol alkoxylate alone significantly reduces the paste viscosity, and this effect is considerably enhanced by the addition of amine dispersants. In particular, combinations of alkoxylated butanol and amine dispersants lead to a faster decrease in viscosity than the addition of butanol alkoxylate alone.

[0034] An organic red pigment was incorporated into various alkoxylate / dispersant mixtures under high shear to obtain pastes with a pigment concentration of 25 wt%. The viscosity of the pastes was determined at shear rates of 1, 10, 100, and 500 s⁻¹. -1 , as already stated. The results are summarized in Table 2. Table 2 Viscosity of 25 wt% pigment pastes (* = viscosity > 10,000,000 mPas) composition 4 5 6 V3 V4 C 12 -Fattyalcohol+PO+EO - - - 75,0 71,0 Butanol+PO / EO (1:1, random, approx. 1 kDa) 75,0 71,0 71,0 - - Diethylamine + PO + EO - 4,0 - - - SMA / Sulfonamine / API - - 4,0 - 4,0 Red pigment Cinilex DPP Red SR2P 25,0 25,0 25,0 25,0 25,0 sum 100,0 100,0 100,0 100,0 100,0 Viscosity (mPas) 1 / s 14380 12440 425 - 1144 10 / s 2621 2304 386 4459 1054 100 / s 817 752 379 1780 987 500 / s 536 506 385 1317 932

[0035] Here too, the examples and comparisons show that butanol alkoxylate alone significantly reduces the paste viscosity, and this effect is considerably enhanced by the addition of amine dispersants. In particular, combinations of alkoxylated butanol and amine dispersants lead to a faster decrease in viscosity than the addition of butanol alkoxylate alone. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2018 184961 A1

[0007] WO 2015 090811 A1

[0008] WO 2018 157965 A1

[0009]